1-phenylalkanecarboxylic acid derivatives for the treatment of neurodegenerative diseases

ABSTRACT

1-Phenylalkanecarboxylic acid derivatives, the processes for the preparation thereof and the use thereof in the treatment and/or prevention of neurodegenerative diseases such as Alzheimer&#39;s disease.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. patentapplication Ser. No. 12/647,069, filed on Dec. 24, 2009, now U.S. Pat.No. 8,022,250, which was a Continuation Application of U.S. patentapplication Ser. No. 10/546,190, filed on Oct. 10, 2006, now U.S. Pat.No. 7,662,995, which was a 371 of International Patent Application No.PCT/EP04/01596, filed Feb. 19, 2004, and claims priority to ItalianPatent Application No. MI2003A000311, filed on Feb. 21, 2003, andItalian Patent Application No. MI2003A002068, filed on Oct. 23, 2003.

The present invention concerns 1-phenylalkanecarboxylic acids, pro-drugsand bioisosters on the carboxylic moiety thereof. The invention is alsodirected to a process for their preparation and the use thereof in theprevention or in the therapeutical treatment of neurodegenerativediseases, in particular Alzheimer's disease.

INTRODUCTION

Alzheimer's disease is a neurodegenerative disorder characterized byatrophy of the cerebral cortex and by a massive loss of cortical neuronsand cholinergic projections of the nucleus basalis towards the cortex.From a histopathologic point of view there is a diffuse presence ofextracellular and perivascular neuritic plaques and intracellularneurofibrillary tangles in the cerebral parenchyma of Alzheimerpatients.

Neuritic plaques are mainly composed of aggregates of a protein with39-43 amino acid residues known as β-amyloid (βA), and, depending on thenumbers of aminoacids, Aβ₃₉, Aβ₄₀, Aβ₄₂ and Aβ₄₃.

In addition to these histopathologic lesions, there is lack in someneurotransmitters, particularly acetylcholine, serotonin, noradrenalin,dopamine, glutamate and substance P. The pharmacological approachesaimed at increasing acetylcholine cerebral levels, mainly throughacetylcholine-esterase inhibitors, attained poor results from theclinical standpoint, or anyhow results which cannot significantlyprevent the progress of the disease. For this reason, in recent yearsinterest has been focused on the mechanisms of formation of the mainpathologic lesions in the brain of the patients, namely both neuriticplaques and neurofibrillary tangles, and more effective therapeuticalapproaches have been looked for.

PRIOR ART

Epidemiological studies evidenced that chronic administration of nonsteroid anti-inflammatory drugs (NSAIDs) significantly decreases theonset of Alzheimer's disease in the population regularly taking thesedrugs. The mechanism underlying such NSAID preventive action has notbeen fully elucidated yet, but is apparently connected with theirability of inhibiting cyclooxygenase (COX) enzymes.

More recently, a novel pharmacological action of some non steroidanti-inflammatory drugs (NSAIDs) has been described: indomethacin,sulindac, ibuprofen and flurbiprofen can selectively reduce theproduction of the most neurotoxic isoform of β-amyloid peptide in cellcultures, namely the form containing 42 amino acids (Aβ₄₂), thusfavouring the release of a less harmful isoform, Aβ₃₈ (Weggen et al.,Nature 2001; 414 (6860): 212-6). However, the inhibition of theproduction of Aβ₄₂, which can be ascribed to the interaction of thesedrugs with γ-secretase (a macromolecular/multiprotein enzymatic complexwith aspartyl-protease activity) has been observed in vitro at very highconcentrations. Plasma and cerebral levels corresponding to the dosagesused in the in vitro experimentation could significantly increase intreated patients the risk of side effects typical of COX inhibitors,such as gastrointestinal bleeding and perforating ulcers.

WO 01/78721 claims a method of preventing, delaying or reversing theprogression of Alzheimer's disease by administering an Aβ₄₂ loweringagent, under conditions in which levels of Aβ₃₈ are increased and levelsof Aβ₄₂ are left unchanged. Furthermore, methods and materials foridentifying and developing Aβ₄₂ lowering agents and methods foridentifying agents that increase the risk of developing, or hastenprogression of, Alzheimer's disease, are disclosed. The examples concernindomethacin and flufenamic acid derivatives, but no examples concerningflurbiprofen derivatives are reported.

Jantzen et al, J Neurosci 2002; 22: 2246-2254, described a flurbiprofenderivative capable of releasing nitric oxide. The paper genericallystates that flurbiprofen derivatives are apparently more efficaciousthan other NSAIDs in clearing β-amyloid deposits, but no mentionconcerning any Aβ₄₂ lowering selective activity is made.

In this therapeutical scenario, and in the light of the potentialproblems of conventional NSAIDs, novel derivatives having more selectiveand more potent inhibitory activity on the peptide Aβ₄₂ while inhibitingto a lesser extent, or not inhibiting at all, cyclooxygenase would be asignificant improvement in therapies aimed at preventing the onset ofAlzheimer's disease and/or at delaying the cognitive decline thatrepresent an early stage disease.

Substituted 1-phenyl-2,2-dialkyl carboxylic derivatives were describedas anti-inflammatory, analgesic and antipyretic agents in GB 1,198,212,U.S. Pat. Nos. 3,978,071, 757,136, GB 1,352,723, JP49100089 and JP50046669.

3-Halo-4-alkyl- or cycloalkyl-substituted 1-phenylcycloalkanecarboxylicderivatives were described in JP-4,7047,375 and FR-2,012,285, assubstances with the same activity.

In the paper from Kuzuna S et al (Takeda Kenkyushoho 1975, 34, 467-473)dealing with a structure-activity study of a series of phenylaceticderivatives, it is generically stated that the introduction of acyclopropane group at the position of α carbon atom decreases theanti-inflammatory and analgesic activities.

In WO 99/41224 novel biaryl-acetic acid derivatives withanti-inflammatory activity as cyclooxygenase-2 inhibitors, useful forthe treatment of a number of diseases, including Alzheimer's disease,are claimed.

SUMMARY OF THE INVENTION

The present invention concerns 1-phenylalkanecarboxylic acids, theirpro-drugs, and bioisosters on the carboxylic moiety, the process for thepreparation thereof, pharmaceutical compositions containing them and theuse thereof in the prevention or therapeutical treatment ofneurodegenerative diseases, in particular Alzheimer's disease.

The compounds of the invention inhibit the release of Aβ₄₂ peptidethereby being able to modulate gamma-secretase activity withoutaffecting other important metabolic processes.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to compounds of general formula (I):

wherein:

-   R and R₁ are the same and are selected from the group of linear or    branched C₁-C₄ alkyl;-   otherwise they form a 3 to 6 carbon atoms ring with the carbon atom    to which they are linked;-   G is:    -   a COOR″ group wherein R″ is H, linear or branched C₁-C₄ alkyl,        C₃-C₆ cycloalkyl or ascorbyl;    -   a CONH₂ or a CONHSO₂R′″ group wherein R′″ is linear or branched        C₁-C₄ alkyl or C₃-C₆ cycloalkyl;    -   a tetrazolyl residue;

R₂ is H, CF₃, OCF₃ or a halogen selected from the group of F, Cl, Br, I,preferably fluorine.

Ar is a group of formula

wherein R₃ represents one or more groups independently selected from:

-   -   halogen as previously defined;    -   CF₃;    -   C₃-C₈ cycloalkyl optionally substituted with one or more C₁-C₄        alkyl and/or oxo groups;    -   CH═CH₂;    -   CN;    -   CH₂OH;    -   methylendioxy or ethylendioxy;    -   NO₂    -   phenyl optionally substituted with one or more of the following        groups: halogen; CF₃; OCF₃; OH; linear or branched C₁-C₄ alkyl;        a saturated heterocycle with at least 4 carbon atoms and at        least 1 heteroatom; C₃-C₈ cycloalkyl in turn optionally        substituted with one or more of the following groups linear or        branched C₁-C₄ alkyl, CF₃ or OH;    -   OR₄ or NHCOR₄ wherein R₄ is CF₃, linear or branched C₂-C₆        alkenyl or alkynyl; benzyl; phenyl optionally substituted with        one or more of the following groups: halogen, CF₃, OCF₃, OH,        linear or branched C₁-C₄ alkyl; a saturated heterocycle with at        least 4 carbon atoms and at least 1 heteroatom; C₃-C₈ cycloalkyl        in turn optionally substituted with one or more of the following        groups: linear or branched C₁-C₄ alkyl, CF₃ or OH;    -   SR₅, SO₂R₅ or COR₅ wherein R₅ is linear or branched C₁-C₆ alkyl;        otherwise Ar is an heterocycle ring selected from the group of        thiophene, benzothiophene, dibenzothiophene, thianthrene,        pyrrole, pyrazole, furan, benzofuran, dibenzofuran, indole,        isoindole, benzofurane, imidazole, benzoimidazole, oxazole,        isoxazole, benzoxazole, thiazole, pyridine, pyrimidine,        pyrazine, pyridazine, quinoline, isoquinoline, quinazoline,        quinoxaline, cinnoline, pyrazole, pyran, benzopyran,        pyrrolizine, phtalazine, 1,5-naphthyridine, 1,3-dioxole,        1,3-benzodioxole, optionally substituted with one or more groups        R₃ as defined above;        pharmaceutically acceptable salts and esters thereof.

A first group of preferred compounds is that in which:

-   R and R₁ form a 3 carbon atoms ring with the carbon atom to which    they are linked;-   R₂ is fluorine;-   G is COOR″, wherein R″ is H, linear or branched C₁-C₄ alkyl, C₃-C₆    cycloalkyl or ascorbyl;-   Ar is phenyl as defined above.

A second group of preferred compounds is that in which:

-   R and R₁ form a 3 carbon atoms ring with the carbon atom to which    they are linked;-   R₂ is fluorine;-   G is CONH₂ or CONHSO₂R′″ wherein R′″ is linear or branched C₁-C₄    alkyl or C₃-C₆ cycloalkyl;-   Ar is phenyl as defined above.

A third group of preferred compounds is that in which:

-   both R and R₁ are methyl;-   R₂ is fluorine;-   G is COOR″ wherein R″ is as defined above;-   Ar is phenyl as defined above.

A fourth group of preferred compounds is that in which:

-   both R and R₁ are methyl;-   R₂ is fluorine;-   G is CONH₂ or CONHSO₂R′″, wherein R′″ is as defined above;-   Ar is phenyl as defined above.

A fifth group of preferred compounds is that in which:

-   R and R₁ form a 3 carbon atoms ring with the carbon atom to which    they are linked;-   R₂ is fluorine;-   G is COOR″ wherein R″ is as defined above;-   Ar is a heterocycle as defined above.

A sixth group of preferred compounds is that in which:

-   both R and R₁ are methyl;-   R₂ is fluorine;-   G is COOR″ wherein R″ is as defined above;-   Ar is a heterocycle as defined above.

Particularly preferred are the following compounds:

-   2-methyl-2(2-fluoro-4′-trifluoromethylbiphen-4-yl)propionic acid    (CHF 4810);-   2-methyl-2(2-fluoro-4′cyclohexyl biphen-4-yl)propionic acid (CHF    4961);-   1-(2-fluoro-4′-trifluoromethylbiphenyl-4-yl)cyclopropanecarboxylic    acid (CHF 5022);-   1-(4′-cyclohexyl-2-fluorobiphenyl-4-yl)cyclopropanecarboxylic acid    (CHF 5023);-   1-(4′-benzyloxy-2-fluorobiphenyl-4-yl)cyclopropanecarboxylic acid    (CHF 5042);-   1-(2-fluoro-4′-isopropyloxybiphenyl-4-yl)cyclopropanecarboxylic acid    (CHF 5044);-   1-(2-fluoro-3′-trifluoromethoxybiphenyl-4-yl)cyclopropanecarboxylic    acid (CHF 5045);-   1-(2-fluoro-4′-trifluoromethoxybiphenyl-4-yl)cyclopropanecarboxylic    acid (CHF 5046);-   1-(2-fluoro-3′-trifluoromethylbiphenyl-4-yl)cyclopropanecarboxylic    acid (CHF 5058);-   1-(4′-cyclopentyl-2-fluorobiphenyl-4-yl)cyclopropanecarboxylic acid    (CHF 5059);-   1-(4′-cycloheptyl-2-fluorobiphenyl-4-yl)cyclopropanecarboxylic acid    (CHF 5060);-   1-(2′-cyclohexyl-2-fluorobiphenyl-4-yl)cyclopropanecarboxylic acid    (CHF 5061);-   1-(2-fluoro-4′-hydroxybiphenyl-4-yl)cyclopropanecarboxylic acid (CHF    5070);-   1-[2-fluoro-4′-(tetrahydropyran-4-yloxy)biphenyl-4-yl]-cyclopropane-carboxylic    acid (CHF 5071);-   1-(2,3′,4′-trifluorobiphenyl-4-yl)cyclopropanecarboxylic acid (CHF    5073);-   1-(3′,4′-dichloro-2-fluorobiphenyl-4-yl)cyclopropanecarboxylic acid    (CHF 5074);-   1-(3′,5′-dichloro-2-fluorobiphenyl-4-yl)cyclopropanecarboxylic acid    (CHF 5075);-   1-(3′-chloro-2,4′-difluorobiphenyl-4-yl)cyclopropanecarboxylic acid    (CHF 5076);-   1-(4-benzo[b]thiophen-3-yl-3-fluorophenyl)cyclopropanecarboxylic    acid (CHF 5077);-   1-(2-fluoro-4′-prop-2-inyloxy-biphenyl-4-yl)-cyclopropanecarboxylic    acid (CHF 5078);-   1-(4′-cyclohexyloxy-2-fluoro-biphenyl-4-yl)-cyclopropanecarboxylic    acid (CHF 5079);-   1-[2-fluoro-4′-(tetrahydropyran-4-yl)-biphenyl-4-yl]-cyclopropanecarboxylic    acid (CHF 5080);-   1-[2-fluoro-4′-(4-oxo-cyclohexyl)-biphenyl-4-yl]-cyclopropanecarboxylic    acid (CHF 5081);-   2-(2″-fluoro-4-hydroxy-[1,1′:4′,1″]tert-phenyl-4″-yl)-cyclopropanecarboxylic    acid (CHF 5083);-   1-[4′-(4,4-dimethylcyclohexyl)-2-fluoro[1,1′-biphenyl]-4-yl]-cyclopropane-carboxylic    acid (CHF 5084);-   1-[2-fluoro-4′-[[4-(trifluoromethyl)benzoyl]ammino][1,1′-biphenyl]-4-yl]-cyclopropanecarboxylic    acid (CHF 5094);-   1-[2-fluoro-4′-[[4-(trifluoromethyl)cyclohexyl]oxy][1,1′-biphenyl]-4-yl]-cyclopropanecarboxylic    acid (CHF 5096);-   1-[2-fluoro-4′-[(3,3,5,5-tetramethylcyclohexyl)oxy][1,1′-biphenyl]-4-yl]-cyclopropanecarboxylic    acid (CHF 5102);-   1-[4′-[(4,4-dimethylcyclohexyl)oxy]-2-fluoro[1,1′-biphenyl]-4-yl]-cyclopropanecarboxylic    acid (CHF 5103);-   1-(2,3′,4″-trifluoro[1,1′:4′,1″-tert-phenyl]-4-yl)-cyclopropanecarboxylic    acid (CHF 5104);-   1-(2,2′,4″-trifluoro[1,1′:4′,1″-tert-phenyl]-4-yl)-cyclopropanecarboxylic    acid (CHF 5105);-   1-(2,3′-difluoro-4″-hydroxy[1,1′:4′,1″-tert-phenyl]-4-yl)-cyclopropane-carboxylic    acid (CHF 5106);-   1-(2,2′-difluoro-4″-hydroxy[1,1′:4′,1″-tert-phenyl]-4-yl)-cyclopropane-carboxylic    acid (CHF 5107);-   2-(2-fluoro-3′,5′-bis(chloro)biphen-4-yl)propionic acid amide (CHF    5125).

A more preferred group of compounds is that in which R and R₁ form a 3carbon atoms ring with the carbon atom to which they are linked;

-   R₂ is fluorine;-   G is COOH;    Ar is phenyl substituted with one or more groups in such a way as    that the log P (the partition coefficient between n-octanol and    water) of the whole molecule is equal or higher than 4.5 as    calculated in silico by using the software QikProp® release version    2.1 (Schrodinger Inc).

It has indeed been found that the higher the log P of the molecule, thegreater is the inhibition potency of the release of Aβ₄₂ peptide andthat particularly potent compounds are those whose log P is equal orhigher than 4.5, preferably higher than 5.0.

Examples of these compounds are CHF 5022, CHF 5074, CHF 5096, CHF 5105,CHF 5106 and CHF 5107.

The invention also relates to the pharmaceutically acceptable salts andesters prepared in order to increase the crossing of thehemato-encephalic barrier.

A further object of the present invention are the compounds of formula(I) as medicaments, in particular the use thereof in the preparation ofpharmaceutical compositions for the treatment and/or the prevention ofneurodegenerative diseases such as Alzheimer's disease.

Still a further object of the invention are solid or liquidpharmaceutical compositions, preferably for the oral use, comprising atleast one compound of formula (I) in admixture with pharmaceuticallyacceptable excipients and/or carriers, for example those described inRemington's Pharmaceutical Sciences Handbook, XVII Ed., Mack Pub., N.Y.,U.S.A.

The compounds of general formula (I) wherein R″ is H can be preparedaccording to methods of literature by palladium-catalyzed reactionbetween an aryl halide of formula (II)

in which R, R₁ and R₂ are as defined above and X is bromine or iodine,preferably iodine, with a boronic acid or ester ArB(OL)₂ in which L isan alkyl chain, under the conditions reported in Scheme 1.

The compounds of formula (II) are commercially available, or can beprepared according to the following synthetic routes.

Derivatives in which R and R₁ are Straight or Branched C₁-C₄ alkyl(IIa).

Said compounds can be prepared according to the synthetic route shown inScheme 2, starting from the arylacetic acids of formula (III) in which Rand R₂ are as defined above and X is bromine or iodine.

The acid of formula (III) is esterified, alkylated, and optionallyhydrolysed if the group G in the final product is COOH.

Derivatives in which R and R₁ Form a 3-6 Carbon Ring with the CarbonAtom to which they are Linked (IIb)

Said compounds are either commercially available, or can be preparedaccording to the synthetic route reported in Scheme 3 in which n is aninteger of 1 to 4.

Boronic acids or the corresponding boronates are either commerciallyavailable or can be prepared from the corresponding halide according tomethods known in literature.

The compounds of formula (I) wherein G is COOR″, where R″ is linear orbranched C₁-C₄ alkyl, C₃-C₆ cycloalkyl or ascorbyl, can be prepared byesterifying the compounds of formula (I) in which G is COOH.

The compounds of formula (I) in which G is CONH₂ or CONHSO₂R′″ where R′″is linear or branched C₁-C₄ alkyl or C₃-C₆ cycloalkyl can be prepared byreaction of the corresponding esters with NH₃ or the amine NH₂SO₂R′″.

The compounds of formula (I) in which G is tetrazolyl can be preparedfrom compounds of formula (I) according to known methods, for exampletransforming the carboxylic acid into amide, dehydrating the amide tonitrile and reacting the latter with tributyltin azide.

EXAMPLES Examples of Chemical Preparation Example 1 Preparation2-methyl-2-(2-fluoro-4′-trifluoromethylbiphen-4-yl)propionic acid (CHF4810) Preparation of methyl[2-(2-fluoro-4′-trifluoromethylbiphen-4-yl)]propionate

A solution of 2-(2-fluoro-4′-trifluoromethylbiphenyl-4-yl)propionic acid(0.2 g, 0.64 mmoles) in methanol (3 ml) is added with 98% sulfuric acid(0.5 g) and refluxed for 2.5 hours. The solvent is removed under vacuum,the residue is taken up with ethyl acetate (5 ml) and washed with a 5%NaHCO₃ solution (5 ml), then with water. The solution is dried overNa₂SO₄ and concentrated under vacuum to afford an oil (0.2 g, 95%).

HPLC-UV purity (215 nm): 99%

Preparation of methyl[2-methyl-2-(2-fluoro-4′-trifluoromethylbiphen-4-yl)]propionate

A solution of methyl[2-(2-fluoro-4′-trifluoromethylbiphen-4-yl)]propionate (0.2 g, 0.61mmoles) in anhydrous THF (3 ml) at 0° C. and under nitrogen atmosphere,is added with 60% NaH (30 mg, 0.75 mmoles). The mixture is stirred for30 minutes and added with CH₃I (70 μl, 0.91 mmoles). After 3 h themixture is concentrated under vacuum and taken up with ethyl acetate (5ml). The resulting solution is washed with a 5% NaHCO₃ solution (5 ml),then with water, dried over Na₂SO₄, concentrated under vacuum to give anoil (0.18 g, 87%) which is used for the subsequent reaction withoutfurther purification.

Preparation of2-methyl-2-(2-fluoro-4′-trifluoromethylbiphen-4-yl)propionic acid

A solution of methyl[2-methyl-2-(2-fluoro-4′-trifluoromethylbiphen-4-yl)]propionate (0.18 g,0.53 mmoles) in ethanol (5 ml) is added with KOH (60 mg, 1 mmol) andkept under stirring for 3 h at room temperature. The mixture is dilutedwith H₂O (5 ml) and the solution is washed with ethyl ether (5 ml). Theorganic phase is discarded. The aqueous phase is acidified to pH=2 withHCl, then extracted with ethyl acetate (10 ml). The organic phase isdried over Na₂SO₄ and concentrated under vacuum to give a white solid,which is purified by flash chromatography on SiO₂ (eluent hexane/ethylacetate 8/2 v/v) to obtain the product as a white solid (16 mg, 10%).

HPLC-UV purity (215 nm): 97%.

¹H NMR (DMSO-d6): 12.56 (s br, 1H); 7.84 (d, 2H); 7.78 (d, 2H); 7.57(dd, 1H); 7.32 (s, 1H); 7.29 (m, 1H); 1.52 (s, 6H);

MS (EI): 326 m/z (M+.), 281, 253.

Following the same procedure and using the suitable reactive, compound,CHF 4961 was prepared.

Example 2 Preparation of 1-(2-fluorobiphenyl-4-yl)cyclopropanecarboxylicacid (CHF 5041) Preparation of 4-bromo-3-fluorobenzyl bromide

A solution of 4-bromo-3-fluorotoluene (10 g, 0.053 moles) in carbontetrachloride (100 ml) is added with N-bromosuccinimide, (NBS; 14 g,0.08 moles). The mixture is refluxed, added with dibenzoyl peroxide (100mg, 0.4 mmoles), refluxed for 1 hour, then cooled at room temperatureand extracted with water. The aqueous phase is discarded, the organicphase is washed with brine, dried over sodium sulfate and concentratedunder vacuum to give an oil (16 g) which is subjected to chromatographyon a silica gel column (150 g), eluting with hexane, to afford theproduct.

Preparation of 4-bromo-3-fluorophenylacetonitrile

A solution of 4-bromo-3-fluorobenzyl bromide (12.2 g, 0.03 moles) inethanol (100 ml) is added with NaCN (2 g, 0.04 moles) and refluxed for 2hours. The mixture is concentrated under vacuum; the resulting residueis taken up with water, then extracted with ethyl acetate. The organicphase is washed with brine, dried over sodium sulfate and concentratedunder vacuum to give a dark oil (10 g), which is subjected tochromatography on a silica gel column (150 g), eluting with hexane:ethylether 7:3, to afford the product in the solid form.

Preparation of 4-bromo-3-fluorophenylcyclopropanenitrile

A solution of 4-bromo-3-fluorophenylacetonitrile (5 g, 23 mmoles) intoluene (20 ml) is added with 35 mmoles of 1,2-dibromoethane, a 50% NaOHaqueous solution (20 ml) and tetrabutylammonium bromide (1.6 g, 5mmoles). The mixture is kept under stirring at room temperature for 5-12hours, then diluted with water and extracted with ethyl acetate. Theorganic phase is washed with 1N HCl, then with brine, finally dried andconcentrated under vacuum to give a brown solid, which is subjected tochromatography on a silica gel column (200 g), eluting with hexane-ethylether 1-1, to afford the product in the solid form.

Preparation of 4-bromo-3-fluorophenylcyclopropanecarboxylic acid

A suspension of 4-bromo-3-fluorophenylcyclopropanenitrile (21 mmoles) inmethanol (10 ml) is added with a 35% NaOH aqueous solution (40 ml) and a35% H₂O₂ aqueous solution (3 ml), then is refluxed for 4 hours, cooledat room temperature and added with 2N HCl (250 ml). The precipitatedsolid is collected by filtration and redissolved in a 5% NaHCO₃ aqueoussolution (300 ml). The insoluble fraction is filtered off and the clearfiltrate is acidified to pH=2 with 2N HCl. The product precipitates as awhite solid, which is recovered by filtration and dried under vacuum.

Preparation of 1-(2-fluorobiphenyl-4-yl)cyclopropanecarboxylic acid

800 mg (3.1 mmoles) of 4-bromo-3-fluorophenylcyclopropanecarboxylic acidand 650 mg (3.4 mmoles) of phenylboronic acid are suspended in 8 ml of a2M K₂CO₃ aqueous solution. The mixture is added with tetrabutylammoniumbromide (960 mg, 3 mmoles) and palladium(II) acetate (40 mg, 0.18mmoles) and heated at 130° C. in a closed reactor for 30 minutes. Aftercooling at room temperature, the mixture is added with 2M HCl (25 ml)and extracted with ethyl acetate. The organic phase is washed with 1NHCl, then with brine, finally dried and concentrated under vacuum togive an oil (1.7 g), which is crystallized from isopropyl ether-hexaneto afford the product as a white solid (0.2 g).

HPLC (215 nm) 98%.

MS (EI; TSQ 700; parameters 180 C; 70 V; 200 uA): 256 (M+.); 210; 196.¹H-NMR (DMSO): 12.41 (s br, 1H); 7.56-7.35 (m, 6H); 7.27 (m, 1H); 7.24(s, 1H); 1.48 (m, 2H); 1.22 (m, 2H).

Following the same procedure as described in Example 1, starting fromthe suitable 4-bromophenylcycloalkanecarboxylic acids and using theappropriate reactives, compounds CHF 5022, CHF 5023 CHF 5042, CHF 5045,CHF 5046, CHF 5058, CHF 5059, CHF 5060, CHF 5061, CHF 5070, CHF 5071,CHF 5073, CHF 5074, CHF 5075, CHF 5076, CHF 5077, CHF 5078, CHF 5079,CHF 5080, CHF 5081, CHF 5083, CHF 5084, CHF 5094, CHF 5096, CHF 5102,CHF 5103, CHF 5104, CHF 5105, CHF 5106, CHF 5107 and CHF 5002 wereprepared.

Example 3 Pharmacological Activity Inhibition of Aβ₄₂ Release in theSupernatant of H4-15× Cells

H4-15× cells (human neuroglioma cells transfected with the human geneencoding for the precursor of β-amyloid protein APP695) were cultured inflasks (in incubator at 37° C., under aqueous vapour saturatedatmosphere with 5% carbon dioxide), in the presence of hygromycin andblasticidin, which maintain the selective pressure for the cellscontinuously expressing the gene of interest.

When the cells reached about 90% confluency, they were collected andre-seeded in 24 wells plates (2×10⁵ cells each), in 0.5 ml of completeculture medium. After approx. 24 hours, when the cells had adhered tothe well surface and reached confluency, the medium of each well wasreplaced with 0.5 ml of fresh culture medium, supplemented with acompound (I) to 100 micromolar final concentration. Each testedconcentration was repeated in triplicate. The molecules used for thetreatment were previously dissolved in dimethylsulfoxide (DMSO) or in adimethylsulfoxide/water mixture, the final concentration of DMSO in thewells not exceeding 1%. Thus the prepared plates were incubated againovernight (14-16 hours); afterwards the cell supernatant was taken fromeach well and Aβ₄₂ and Aβ₄₀ proteins were quantitated. The assay wascarried out with an instrumentation for microplates chemoluminescenceanalysis, which allows to separately quantify the two proteins and isbased on the immobilization of an analyte-antibody complex onparamagnetic microbeads. One of the antibodies of this complex is markedwith a ruthenium compound which, upon electrochemical excitement, givesa light signal, having intensity proportional to the amount of analytepresent.

Inhibition of cyclooxygenase-1 (COX-1) in Rat Whole Blood

Whole blood was taken from the rat abdominal aorta and immediatelyplaced in heparinized tubes. Aliquots of heparinized blood (500 μl) werepreincubated with 100 μM concentration of the tested compounds or withthe only carrier (DMSO) for 1 h at 37° C. Eicosanoid production wasinduced by addition of calcium ionophore A23187 (final concentration5×10⁻⁵ M) and was interrupted after 30 minute incubation by quicklyplacing the samples in dry ice. Thereafter, samples were centrifuged(12000 g×3 minutes a 4° C.) and the production of TxB₂ thromboxane B2was calculated by radioimmunoassay.

The results expressed as percent inhibition of Aβ₄₂ release at 100 μMand percent COX-1 inhibitory activity at the same concentration arereported in Table 1. Flurbiprofen used as comparison at the sameconcentration showed approx. 25% inhibition of Aβ₄₂ release and 100%COX-1 inhibitory activity.

TABLE 1 Percent inhibition of Aβ₄₂ release and percent COX-1 inhibitoryactivity of representative compounds of the invention at 100 μMconcentration. % inhibition of Aβ₄₂ % COX-1 inhibitory Compound releaseactivity CHF 4961 76.6 5.2 CHF 4810 58.0 — CHF 5022 55.4 0.0 CHF 504556.4 8.3 CHF 5046 70.4 2.6 CHF 5058 54.8 0.0 CHF 5070 22.4 0.0 CHF 507128.1 0.4 CHF 5073 67.4 4.8 CHF 5074 79.2 0.5 CHF 5076 71.4 5.5 CHF 507857.5 3.6 CHF 5080 51.8 0.3 CHF 5081 52.3 6.1 CHF 5083 81.1 — CHF 509670.0 0.8 CHF 5105 90.7 1.9 CHF 5106 79.9 0.0 CHF 5107 83.3 1.1

1. A process for the preparation of a compound of formula (I):

wherein: R and R₁ form a 3 to 6 carbon atoms ring with the carbon atomto which they are linked; and R₃ represents one or more groupsindependently selected from: halogen selected from the group consistingof F, Cl, Br, and I; CF₃; C₃-C₈ cycloalkyl optionally substituted withone or more C₁-C₄ alkyl and/or oxo groups; phenyl optionally substitutedwith one or more of the following groups: halogen as defined above; CF₃;OCF₃; OH; linear or branched C₁-C₄ alkyl; a saturated heterocycle withat least 4 carbon atoms and at least 1 heteroatom; C₃-C₈ cycloalkyl inturn optionally substituted with one or more of the following groupslinear or branched C₁-C₄ alkyl, CF₃ or OH; OR₄ or NHCOR₄ wherein R₄ isCF₃, linear or branched C₂-C₆ alkenyl or alkynyl; benzyl; phenyloptionally substituted with one or more of the following groups:halogen, CF₃, OCF₃, OH, linear or branched C₁-C₄ alkyl; a saturatedheterocycle with at least 4 carbon atoms and at least 1 heteroatom;C₃-C₈ cycloalkyl in turn optionally substituted with one or more of thefollowing groups: linear or branched C₁-C₄ alkyl, CF₃ or OH; saidprocess comprising: condensing a boronic acid or ester ArB(OL)₂, inwhich Ar is phenyl and L is an alkyl chain, with an aryl halide offormula (II):

wherein R and R₁ are the same as defined above, X is a halogen atomselected from bromine or iodine; and wherein said condensing iscatalyzed by palladium.
 2. A process according to claim 1, wherein X isiodine or bromine.
 3. A process according to claim 1, wherein R and R₁together with the carbon atom to which they are attached form a ringcontaining 3 carbon atoms.
 4. A process according to claim 2, wherein Rand R₁ together with the carbon atom to which they are attached form aring containing 3 carbon atoms.
 5. A process according to claim 3,wherein R₃ is Cl.
 6. A process according to claim 4, wherein R₃ is Cl.7. A process according to claim 1, wherein said aryl halide of formula(II) is prepared by a process comprising: (a) transforming a4-halo-3-fluorotoluene into a 4-halo-3-fluorobenzylbromide; (b)transforming of said 4-halo-3-fluorobenzylbromid into the corresponding4-halo-3-fluorophenylacetonitrile; (c) condensing said4-halo-3-fluorophenylacetonitrile with a compound of formulaBr—CH₂—(CH₂)_(n)—CH₂—Br, in which n is 0 or an integer of 1 to 4, toobtain the corresponding 4-halo-3-fluorophenylcycloalkylnitrile; and (d)transforming said 4-halo-3-fluorophenylcycloalkylnitrile into4-halo-3-fluorocycloalkylcarboxylic acid.
 8. A according to claim 7,wherein said compound of formula Br—CH₂—(CH₂)_(n)—CH₂—Br is1,2-dibromoethane.
 9. A process according to claim 2, wherein said arylhalide of formula (II) is prepared by a process comprising: (a)transforming a 4-halo-3-fluorotoluene into a4-halo-3-fluorobenzylbromide; (b) transforming of said4-halo-3-fluorobenzylbromid into the corresponding4-halo-3-fluorophenylacetonitrile; (c) condensing said4-halo-3-fluorophenylacetonitrile with a compound of formulaBr—CH₂—(CH₂)_(n)—CH₂—Br, in which n is 0 or an integer of 1 to 4, toobtain the corresponding 4-halo-3-fluorophenylcycloalkylnitrile; and (d)transforming said 4-halo-3-fluorophenylcycloalkylnitrile into4-halo-3-fluorocycloalkylcarboxylic acid.
 10. A according to claim 9,wherein said compound of formula Br—CH₂—(CH₂)_(n)—CH₂—Br is1,2-dibromoethane.
 11. A process according to claim 3, wherein said arylhalide of formula (II) is prepared by a process comprising: (a)transforming a 4-halo-3-fluorotoluene into a4-halo-3-fluorobenzylbromide; (b) transforming of said4-halo-3-fluorobenzylbromid into the corresponding4-halo-3-fluorophenylacetonitrile; (c) condensing said4-halo-3-fluorophenylacetonitrile with a compound of formulaBr—CH₂—(CH₂)_(n)—CH₂—Br, in which n is 0 or an integer of 1 to 4, toobtain the corresponding 4-halo-3-fluorophenylcycloalkylnitrile; and (d)transforming said 4-halo-3-fluorophenylcycloalkylnitrile into4-halo-3-fluorocycloalkylcarboxylic acid.
 12. A according to claim 11,wherein said compound of formula Br—CH₂—(CH₂)_(n)—CH₂—Br is1,2-dibromoethane.
 13. A process according to claim 4, wherein said arylhalide of formula (II) is prepared by a process comprising: (a)transforming a 4-halo-3-fluorotoluene into a4-halo-3-fluorobenzylbromide; (b) transforming of said4-halo-3-fluorobenzylbromid into the corresponding4-halo-3-fluorophenylacetonitrile; (c) condensing said4-halo-3-fluorophenylacetonitrile with a compound of formulaBr—CH₂—(CH₂)_(n)—CH₂—Br, in which n is 0 or an integer of 1 to 4, toobtain the corresponding 4-halo-3-fluorophenylcycloalkylnitrile; and (d)transforming said 4-halo-3-fluorophenylcycloalkylnitrile into4-halo-3-fluorocycloalkylcarboxylic acid.
 14. A according to claim 13,wherein said compound of formula Br—CH₂—(CH₂)_(n)—CH₂—Br is1,2-dibromoethane.
 15. A process according to claim 5, wherein said arylhalide of formula (II) is prepared by a process comprising: (a)transforming a 4-halo-3-fluorotoluene into a4-halo-3-fluorobenzylbromide; (b) transforming of said4-halo-3-fluorobenzylbromid into the corresponding4-halo-3-fluorophenylacetonitrile; (c) condensing said4-halo-3-fluorophenylacetonitrile with a compound of formulaBr—CH₂—(CH₂)_(n)—CH₂—Br, in which n is 0 or an integer of 1 to 4, toobtain the corresponding 4-halo-3-fluorophenylcycloalkylnitrile; and (d)transforming said 4-halo-3-fluorophenylcycloalkylnitrile into4-halo-3-fluorocycloalkylcarboxylic acid.
 16. A according to claim 15,wherein said compound of formula Br—CH₂—(CH₂)_(n)—CH₂—Br is1,2-dibromoethane.
 17. A process according to claim 6, wherein said arylhalide of formula (II) is prepared by a process comprising: (a)transforming a 4-halo-3-fluorotoluene into a4-halo-3-fluorobenzylbromide; (b) transforming of said4-halo-3-fluorobenzylbromid into the corresponding4-halo-3-fluorophenylacetonitrile; (c) condensing said4-halo-3-fluorophenylacetonitrile with a compound of formulaBr—CH₂—(CH₂)_(n)—CH₂—Br, in which n is 0 or an integer of 1 to 4, toobtain the corresponding 4-halo-3-fluorophenylcycloalkylnitrile; and (d)transforming said 4-halo-3-fluorophenylcycloalkylnitrile into4-halo-3-fluorocycloalkylcarboxylic acid.
 18. A according to claim 17,wherein said compound of formula Br—CH₂—(CH₂)_(n)—CH₂—Br is1,2-dibromoethane.